Patent Literature 1 below, for example, describes an image processor of a background art. The image processor includes a frame memory configured with an SDRAM (Synchronous Dynamic Random Access Memory) and a motion search unit connected to the frame memory. The frame memory holds an image to be coded, a reference image for rough search, and a reference image for fine search. The reference image for rough search is produced in advance by reduction and stored in the frame memory. The motion search unit firstly reads an image to be coded and the reference image for rough search from the frame memory and performs motion search with these images, so as to obtain a motion vector as a result of rough search. Then the motion search unit reads the reference images of the areas surrounding this motion vector among the reference images for fine search from the frame memory and performs motion search with the image to be coded and this reference images, so as to obtain a motion vector as a result of fine search.